I've busted my nose quite a bit from playing basketball with kids at the park, never broken it though, just a bloody mess.
I used to ride my BMX bike everyday until one day I popped a wheelie and my handlebars flew off and I landed on my back in a ditch. It knocked the wind out of me and I had to literally crawl back home.
My favorite "injury" though was when I took karate (when I was younger) and after going through an hour long semi-intensive youth class, with no water, I told my teacher I wanted to try out the intensive adult training, so he let me. I lasted 15 mins and everything turned all slowmo and I collapsed on the floor in a pool of sweat, apparently I dehydrated.